U.S. Pat. No. 7,094,006 discloses a cutting tool in which the cutting insert has two abutment surfaces transverse to two side surfaces and the insert pocket has two sidewalls transverse to the base wall. When the cutting insert is retained in the insert pocket a first abutment surface abuts a first sidewall of the insert pocket, a second abutment surfaces abuts a second sidewall of the insert pocket and a side surface of the cutting insert abuts the base wall of the insert pocket. The first sidewall is elongated in form, extending longitudinally rearwardly from a forward end of the cutting tool. The first side wall is located on a lower support member in the form of a relatively thin narrow strip of the tool body.
Insert securing methods that do not require a lower support member of the type described above use specially designed protrusions (or recesses) extending from the tool shank, abutting matching recesses (protrusions) in the base of the cutting insert, as described, for example, in DE022005016610U1 and EP1657012. EP1657012 discloses a securing method with an elevated boss having studs oriented around the screw bore in a double-Y formation. While the insert is in a secured position, the boss and studs of the cutting insert abut matching recesses in the insert pocket. The abutment surfaces described in DE022005016610U1 and EP1657012 have a non-parallel orientation with respect to a screw bore axis. This allows for machining forces exerted onto the cutting insert and eventually the abutment surfaces, to have an element in the direction of the screw bore axis. Swiss-type automatic machines are known to require the use of small cutting tools secured with high accuracy in the machine. In this field, cutting edge location accuracy is attained either by an accurate abutment (which is most likely achieved by a rather expensive grinding of the abutment surfaces) or by grinding the cutting portion. Achieving an accurate abutment is somewhat difficult when the abutment surfaces are created by form-pressing and sintering (without grinding) as disclosed, for example, in DE022005016610U1.